don't throttle when using hardware encoding

MediaBrowser.Api/Playback/BaseStreamingService.cs

@@ -1118,22 +1118,23 @@ namespace MediaBrowser.Api.Playback
 
         private void StartThrottler(StreamState state, TranscodingJob transcodingJob)
         {
-            if (EnableThrottling(state) && state.InputProtocol == MediaProtocol.File &&
+            if (EnableThrottling(state) && !string.Equals(state.OutputVideoCodec, "copy", StringComparison.OrdinalIgnoreCase))
-                           state.RunTimeTicks.HasValue &&
-                           state.VideoType == VideoType.VideoFile &&
-                           !string.Equals(state.OutputVideoCodec, "copy", StringComparison.OrdinalIgnoreCase))
-            {
-                if (state.RunTimeTicks.Value >= TimeSpan.FromMinutes(5).Ticks && state.IsInputVideo)
             {
                 transcodingJob.TranscodingThrottler = state.TranscodingThrottler = new TranscodingThrottler(transcodingJob, Logger, ServerConfigurationManager);
                 state.TranscodingThrottler.Start();
             }
         }
-        }
 
         protected virtual bool EnableThrottling(StreamState state)
         {
-            return true;
+            // do not use throttling with hardware encoders
+            return state.InputProtocol == MediaProtocol.File &&
+                state.RunTimeTicks.HasValue &&
+                state.RunTimeTicks.Value >= TimeSpan.FromMinutes(5).Ticks &&
+                state.IsInputVideo && 
+                state.VideoType == VideoType.VideoFile &&
+                !string.Equals(state.OutputVideoCodec, "copy", StringComparison.OrdinalIgnoreCase) &&
+                string.Equals(GetVideoEncoder(state), "libx264", StringComparison.OrdinalIgnoreCase);
         }
 
         private async Task StartStreamingLog(TranscodingJob transcodingJob, StreamState state, Stream source, Stream target)